Project Mercury

Started in 1958 and completed in 1963, Project Mercury was the United States' first human-in-space program. The objectives of the program, which made six manned flights from 1961 to 1963, were to orbit a manned spacecraft around Earth, to investigate human ability to function in space, and to recover both man and spacecraft safely. Project Mercury was a success and led to Project Gemini.

The Mercury Seven

The Mercury Seven were the original seven astronauts designated to fly in Project Mercury. They were M. Scott Carpenter, L. Gordon Cooper, John Glenn, Virgil "Gus" Grissom, Walter "Wally" Schirra, Alan Shepard, and Donald "Deke" Slayton. Selected for their performance in the Air Force, several of these pioneer astronauts (including Wally Schirra) flew in all NASA rocket spacecraft - from Mercury to Gemini to Apollo.

The successful mission of Apollo 11 could not have been conducted without their efforts, for which one (Gus Grissom) gave his life in the Apollo 1 tragedy, alongside fellow astronauts Ed White and Roger Chaffee.

Donald K. Slayton did not fly a Mercury mission. The flight surgeons grounded him for nearly a decade and a half after finding that he suffered from an occasional dysrhythmia of the heart. The other six astronauts then recommended to NASA administration that the astronaut corps should have a permanent chief, chosen among their number, and chose Slayton to fill that position. Slayton was the only chief that the astronaut corps ever had. He would finally fly the Apollo-Soyuz Test Project mission in 1975, the last mission flown with Project Apollo hardware.